The instant invention is in the field of crossbows and more specifically in the field of devices and methods for de-cocking a crossbow. The classic crossbow is cocked by hand and de-cocked by shooting a bolt from the crossbow since triggering a cocked crossbow without loading a bolt is likely to damage the crossbow. Shooting a bolt into the ground or into a tree to de-cock a crossbow is likely to damage the bolt. Shooting a bolt into the air to de-cock a crossbow is dangerous and is likely to result in a lost bolt. Devices have been invented for de-cocking a crossbow without shooting a bolt from the crossbow. For example, the CONCORDE crossbow by PARKER BOWS uses a CO2 powered de-cocking system built into the crossbow. U.S. Pat. Nos. 6,286,496; 8,375,928; and 8,578,917 disclose an electric motor powered clockwork gear and clutch system to de-cock a crossbow. U.S. Pat. Nos. 5,220,906 and 6,799,566 disclose an electric motor powered jack screw system to de-cock a crossbow. US Patent Application Publication 2014/0305417 discloses a hydraulic cylinder system to dc-cock a crossbow. It would be an advance in the art of devices and methods for de-cocking a crossbow if a device were discovered that could be conveniently attached to a crossbow for dc-cocking the crossbow, which device was less obtrusive, less complicated and safer to use than the devices of the prior art.